+Jeroen Wiert Pluimers OK. Let’s look a bit at how this works. There are several competing standards/ways to use a security token. Typically you’ll decide between the two most used ones. As a CCID device AKA SmartCard with OpenSC or using gpg-agent. And that’s an either/or question. Some of the security tokens can only work with gpg-agent, some can do both (but not at the same time) and some are only useful as CCID style (e.g. the Nitrokey HSM).

OK. So now we look at platforms. CCID using OpenSC mostly works everywhere, but you might need to install some additional software depending on your OS. Older versions of MacOS X were notoriously bad, since (High) Sierra it has become better.

On Linux it again really depends. The gnome-keyring-agent that is active in a Gnome session really messes everything up, so better deactivate that. Which is not really trivial. But you have to have a socket for ssh-agent to pick up the key, so some stuff goes to your .bash.rc and you have to make some changes to Gnome config.

If you want to use a Yubikey for 2FA, note that it cannot do TOTP (Time based One Time Password) which Amazon wants for AWS auth. So you need another helper app on your computer.